Robotic Process Automation (RPA)

Robotic Process Automation (RPA)

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  • 1.  Calculate Mathematical Expression

    Posted Mon May 10, 2021 10:54 AM
    I am trying to get the absolute value of a number (dynamic) and to do that I am using the Calculate Mathematical Expression command, but I can't manage to make it work when using variables in the expression. It does work if I manually insert the values inside the expression, but it's useless that way. Here is what I am trying to do:
    defVar --name number --type Numeric
defVar --name outputValue --type Numeric
setVar --name "${number}" --value "1.2"
evaluate --expression "Math.Abs(${number})" outputValue=value
logMessage --message "${outputValue}" --type "Info"​

    The error I get:
    DynamicExpresso.NoApplicableMethodException: No applicable method 'Abs' exists in type 'Math' (at index 5).
   at DynamicExpresso.Parsing.Parser.ParseMethodInvocation(Type type, Expression instance, Int32 errorPos, String methodName)
   at DynamicExpresso.Parsing.Parser.ParseMemberAccess(Type type, Expression instance)
   at DynamicExpresso.Parsing.Parser.ParseIdentifier()
   at DynamicExpresso.Parsing.Parser.ParsePrimary()
   at DynamicExpresso.Parsing.Parser.ParseUnary()
   at DynamicExpresso.Parsing.Parser.ParseMultiplicative()
   at DynamicExpresso.Parsing.Parser.ParseAdditive()
   at DynamicExpresso.Parsing.Parser.ParseTypeTesting()
   at DynamicExpresso.Parsing.Parser.ParseComparison()
   at DynamicExpresso.Parsing.Parser.ParseLogicalAnd()
   at DynamicExpresso.Parsing.Parser.ParseLogicalOr()
   at DynamicExpresso.Parsing.Parser.ParseConditional()
   at DynamicExpresso.Parsing.Parser.ParseAssignement()
   at DynamicExpresso.Parsing.Parser.ParseExpressionSegment(Type returnType)
   at DynamicExpresso.Parsing.Parser.Parse()
   at DynamicExpresso.Interpreter.ParseAsLambda(String expressionText, Type expressionType, Parameter[] parameters)
   at WDG.Automation.Base.EvaluateCommand.Execute(AutomationContext context)
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at WDG.Automation.Language.ErrorHandler.m0nvU46Nja(Exception  )
   at WDG.Automation.Language.ErrorHandler.HandleExecutionExceptionIfNeeded(Exception exception, IAutomationCommand command)
   at WDG.Automation.Language.CommandInterpreter.<Run>d__12.vQ7xHXNECMOJPEvfGI5(Object , Object , Object )
   at WDG.Automation.Language.CommandInterpreter.<Run>d__12.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at WDG.Automation.Language.ScriptInterpreter.<RunCore>d__17.MoveNext()​


    Am I doing something wrong or is this a bug?



    ------------------------------
    Vinicius Marques
    ------------------------------


  • 2.  RE: Calculate Mathematical Expression

    Posted Tue May 11, 2021 05:53 AM
    Hi vinicius,

    I don't think RPA has Abs built in.  But you can caculate it.  See https://en.wikipedia.org/wiki/Absolute_value

    ------------------------------
    NIGEL CROWTHER
    ------------------------------

    Original Message


  • 3.  RE: Calculate Mathematical Expression

    Posted Tue May 11, 2021 06:03 AM
    Oh I see the problem.  It works if you put in an actual number, but not a variable.  I think that is a bug!

    ------------------------------
    NIGEL CROWTHER
    ------------------------------

    Original Message


  • 4.  RE: Calculate Mathematical Expression

    Posted Sun May 16, 2021 01:39 PM

    Here's a similar issue that i resolved with the code below.

    Math.Pow(Convert.ToDouble(${vInteger}),2)

    -The reported problem happens because .NET does not understand IBM RPA's Numeric type (i.e. the type vInteger is declared as). So when the underlying engine behind evaluate command tries to evaluate Math.Pow(${vInteger},2), it can't find any Pow method accepting a NumericVariant type. The same would happen for any method where you pass a variable as a parameter. No .NET method will understand any IBM RPA's type, so a explicit cast is needed. Thankfully, the engine understands conversion at runtime, so whenever you run into this type of problem, try using one of those methods from .NET's Convert class.



    ------------------------------
    ZACHARY SILVERSTEIN
    ------------------------------

    Original Message


  • 5.  RE: Calculate Mathematical Expression

    Posted Mon May 17, 2021 03:42 AM
    Thanks Zach

    ------------------------------
    NIGEL CROWTHER
    ------------------------------

    Original Message


  • 6.  RE: Calculate Mathematical Expression

    Posted Mon May 17, 2021 08:18 AM
    Thanks!

    ------------------------------
    Vinicius Marques
    ------------------------------

    Original Message


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